Michael Donley is Secretary of the Air Force. This is the third of four op-eds Sec. Donley wrote exclusively for Breaking Defense on the future of the Air Force. Today’s piece deals with the difficult decisions the Air Force must make to preserve its readiness to respond to crises around the world. We are running one op-ed a day, Tuesday through Friday.

Over the past decade, the Air Force has fielded new and impressive warfighting capabilities in support of joint and coalition operations. Bolstered by combat experience, our military has never been stronger.

At the same time, the sustained focus on Iraq and Afghanistan has come with an indirect cost. While the Air Force has met the demands of a high operational tempo in support of these and other operations, this has inevitably taken a toll on our weapon systems and people, putting a strain on the overall readiness of the force. We have seen a steady decline in unit readiness since 2003.

Given the projected decline in defense budgets, we have made a strategic choice to trade size in order to protect a high quality and ready force that will improve in capability over time. Air Force and Department of Defense leaders are working hard to avoid a hollow military: one that looks good on paper, but has more units and equipment than it can support, lacks the resources to adequately man, train and maintain them, or to keep up with advancing technologies.

“Readiness” can be generally defined as the ability of a unit to provide the capabilities or outputs for which it was designed when and where needed. While protecting future readiness includes modernizing the force (a separate subject [click here to read Sec. Donley on modernization]), creating combat readiness in the near term is a complex task mostly involving the intersection of personnel, materiel, and training. This includes balancing time between operational and training commitments, finding the right combination of funding from different sources, and effectively managing these resources to achieve the desired effects.

Mitigating the risk associated with a smaller military requires a ready force. When units are called to deploy on short notice, a larger force structure provides capacity to reinforce units where some aircraft may be unavailable due to maintenance, repair or modification and when personnel are in training status or educational programs, or positions are vacant. The larger capacity can compensate for shortages in personnel and materiel readiness.

Given the resources available, however, we have reached a point where this larger force structure cannot be adequately sustained. If we attempt to sustain current force levels with rising personnel and operational costs, there will be fewer resources available to support our excess capacity of installations, maintain existing aircraft inventories and other vital equipment, or invest in future capabilities.

A smaller force with less capacity requires greater attention to ensuring fully adequate personnel levels, availability of aircraft, and training to support the full range of mission requirements. These factors become more critical because shortages in aircraft availability or key personnel will have a larger effect on the overall readiness of the force. With a smaller force, including all active, guard and reserve elements, there is less marginal capacity to meet operational needs. The total force must thus be more ready to meet near-term contingencies, including those that may involve contested operational environments.

For example, over the past decade the ability of combat air forces to do full-spectrum training has been hampered by operational commitments focused on very specific counter-insurgency missions and air-to-ground support. Training to establish and sustain air superiority and to suppress air defenses has understandably received less emphasis.

As we rebuild full-spectrum readiness, adding resources for more flying hours to support training must be matched with the resources for maintenance to ensure aircraft availability. And to be fully effective, training must also be supported with flight simulators and training ranges that emulate the modern threat environments our pilots may likely face.

This is a work in progress and we would like to be much better than we are in forecasting readiness “outputs” based on resource “inputs.” Nonetheless, we can recognize what does not work – negative trends or potential threats to readiness on the horizon that are reason for concern.

Critical operations and maintenance activities currently being paid for with supplemental, Overseas Contingency Operations funding are especially problematic. Several funding lines for Remotely Piloted Aircraft [aka UAVs] and other ISR platforms, for example, should be retained as part of our future force but are not yet part of our base budget. These activities must eventually migrate from OCO funding to an adjusted base budget. If the base budget is not adjusted, these capabilities will need to be retired or, alternatively, if incorporated without increasing the total budget, they will squeeze out other forces and capabilities.

Other threats to readiness include personnel and operational costs rising faster than the budget; savings from defense cuts not being adequately reapplied into readiness-related activities; and the inability to make or implement strategic choices, like reducing force structure or installations, that would help to consolidate resources and protect a quality force.

The concept of “tiered” readiness, through which some units are resourced for higher levels of readiness than others, also bears close scrutiny. Air Force skepticism of this approach is grounded in two strategic realities. First, we support several Combatant Command missions that require 24/7 support, including various space operations such as missile warning, command, control and communications, and GPS operations. Cyber defense and intelligence, surveillance, and reconnaissance are also 24/7 missions that provide indications and warning of critical events and threats for our national leadership. Operational readiness for these units is a continuous requirement.

These and other activities like special operations and personnel recovery involve complex and exacting missions requiring a high degree of individual and unit proficiency. Standing intercontinental ballistic missiles alert for nuclear deterrence is another example where a sustained, higher state of readiness makes sense at both strategic and operational levels. At the strategic level, a ready nuclear deterrent enables freedom of action by ensuring that no other country is able to threaten the use of nuclear weapons in order to limit or deter US policy options. At the operational level, within the nuclear triad of ICBMS, submarine-launched ballistic missiles, and nuclear-capable bombers, it is ICBMs that maintain the highest readiness posture at the least cost, compensating for rotational or other operational constraints in the other two legs.

High priority missions such as those outlined above cannot be done adequately, and in some cases cannot be done safely, at lower levels of readiness.

A second strategic reality is that the range, speed and striking power of air forces make them among the most flexible and agile elements of the joint force. In support of US defense strategy, air forces are inherently capable of responding quickly and can be shifted on relatively short notice between critical theaters of operation. Intentionally posturing the Air Force for lower readiness and a long buildup to full combat effectiveness would negate the essential strategic advantages of airpower.

In the politics of defense spending, there are many advocates for protecting hometown units and bases, and many advocates for new equipment of all kinds. As the defense budget declines, the political default in Washington thus risks too many units and bases than we can adequately support, with more modernization programs than we can afford. In this competitive stew, it falls to the Defense Department and the services to protect the readiness of the force.

In the past 35 years of my professional experience, the Air Force has been called upon more than 150 times to conduct combat or humanitarian operations in more than 50 countries around the world. Combat sorties in the CENTCOM area have continued uninterrupted since 1991. The completion of combat operations in Iraq and Afghanistan are important milestones that should provide an opportunity to reset the force, but other international security challenges remain and, in some cases, are growing. America will need a ready Air Force.

This is the third of four op-eds written by Sec. Donley exclusively for Breaking Defense. Click here to read the whole series.